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# QLPreviewReply

The class you create when providing a data-based Quick Look preview extension.

```
class QLPreviewReply
```

## Overview

Create an instance of [`QLPreviewReply`](/documentation/QuickLookUI/QLPreviewReply) from the method [`providePreview(for:completionHandler:)`](/documentation/QuickLookUI/QLPreviewingController/providePreview(for:completionHandler:)) in your subclass of [`QLPreviewProvider`](/documentation/QuickLookUI/QLPreviewProvider). Create an instance to return data; for example, an image, PDF, or HTML; that the system displays as the preview for the content that the system indicates with [`QLFilePreviewRequest`](/documentation/QuickLookUI/QLFilePreviewRequest).

## Topics

### Creating a preview reply

[`-  initWithFileURL:`](/documentation/QuickLookUI/QLPreviewReply/init(fileURL:))

Creates a preview reply from an existing file URL.

### Create a PDF preview reply

[`init(forPDFWithPageSize:createDocumentUsing:)`](/documentation/QuickLookUI/QLPreviewReply/init(forPDFWithPageSize:createDocumentUsing:))

### Generating a preview reply

[`init(dataOfContentType:contentSize:createDataUsing:)`](/documentation/QuickLookUI/QLPreviewReply/init(dataOfContentType:contentSize:createDataUsing:))

### Drawing a preview reply

[`init(contextSize:isBitmap:drawUsing:)`](/documentation/QuickLookUI/QLPreviewReply/init(contextSize:isBitmap:drawUsing:))

### Inspecting a preview reply

[`title`](/documentation/QuickLookUI/QLPreviewReply/title)

The title for the system to display with the preview.

[`attachments`](/documentation/QuickLookUI/QLPreviewReply/attachments)

The attachments for a preview reply that provide additional data for the system to display the preview.

[`stringEncoding`](/documentation/QuickLookUI/QLPreviewReply/stringEncoding-8ahm8)

### Instance Properties

[`stringEncoding`](/documentation/QuickLookUI/QLPreviewReply/stringEncoding-1k9kb)

String encoding for text or html based previews. Defaults to NSUTF8StringEncoding.

## Relationships

### Conforms To

[`Hashable`](/documentation/Swift/Hashable)

[`NSObjectProtocol`](/documentation/ObjectiveC/NSObjectProtocol)

[`CVarArg`](/documentation/Swift/CVarArg)

[`Equatable`](/documentation/Swift/Equatable)

[`CustomStringConvertible`](/documentation/Swift/CustomStringConvertible)

[`CustomDebugStringConvertible`](/documentation/Swift/CustomDebugStringConvertible)

### Inherits From

[`NSObject-swift.class`](/documentation/ObjectiveC/NSObject-swift.class)

---

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